llms.txt in 2026: We Publish One. Here's What It Actually Does.

We publish an llms.txt and an llms-full.txt on this site. If you read the rest of this post, you might reasonably ask why we bothered.

Short version: it costs nothing, it does no harm, and it is not the thing doing any real work. If you are deciding whether to spend an afternoon on it, the honest answer is spend five minutes instead — and then go read our guide on what actually makes a site readable to AI crawlers, because that part is not optional the way this one is.

What llms.txt was supposed to do

The idea, proposed in 2024, is a plain-text file at your domain root that hands a language model a curated, markdown-formatted summary of your site — the parts worth reading, without the navigation chrome and cookie banners a normal crawl picks up. It reads like robots.txt for meaning instead of access: not "you may crawl this," but "here is what matters if you do."

It's a reasonable idea. The problem is not the idea. The problem is that essentially nobody who could act on it decided to.

What Google has actually said

At Google Search Central Live, Google's Gary Illyes confirmed Google does not support llms.txt and has no plans to. He compared it directly to the keywords meta tag — a field search engines stopped reading over a decade ago because it's written by the site operator and therefore tells you nothing they didn't already choose to claim about themselves.

John Mueller went further in a public reply: "Google doesn't use llms.txt or llms-author.txt. I don't know of any other crawler / llm confirming they're using these." Asked about the related content-signal robots.txt directive, he added that no crawler or LLM uses it either — "it was made up by a CDN, afaik it has no effects whatsoever" — and that shipping unsupported directives is maintenance burden with no upside.

That is about as direct as a platform statement gets. Not "we're evaluating it." Not "support is coming." Nobody is using it, and nobody we know of is planning to.

What actually happens to a published llms.txt file

Google's disinterest would matter less if some other assistant had adopted the file instead. So the more useful question is behavioural: when a domain publishes one, does anything actually request it?

Ahrefs answered this at scale in May 2026, analysing server logs and bot traffic across 137,210 domains. The numbers:

• 28% of domains in the sample publish a valid llms.txt.
• 97% of those files received zero requests for the entire month.
• Of the 3% that got any traffic at all, 96% of requests came from bots — but a mix of crawlers, agents and scrapers, not specifically the assistants the file is meant for. Named AI retrieval bots like PerplexityBot and OAI-SearchBot accounted for only about 1% of the requests these files did receive.
• On domains with no llms.txt at all, AI bots made zero speculative requests for one. They don't go looking. A crawler that respects llms.txt on the sites that have it would probe for it everywhere, the way every crawler probes for robots.txt on every domain it touches. That probing does not happen, which is a stronger signal than the low fetch rate on its own: the file isn't being ignored occasionally, it isn't part of any crawler's routine at all.

Put together: publishing the file gets you into a small minority (28%) who did the extra work, and of that minority, 97% got nothing for it.

Why we still have one

None of this makes llms.txt harmful, and the cost of publishing one is close to zero — it's a static file, not an integration. What we actually rely on to be readable by ChatGPT, Claude and Perplexity is entirely different, and it's the same lesson we keep landing on when we check whether a page is visible to AI crawlers at all: the thing that matters is whether the page itself — the actual HTML a crawler receives at the actual URL — contains real content, unblocked, with no JavaScript required to render it.

That's a robots.txt that names AI crawlers explicitly instead of leaving them to guess, and a page that returns full content on the first request, no script execution needed. llms.txt is neither of those things — it's a side-channel a wildly small handful of crawlers might, unverified, glance at once. We keep ours published because it costs one file and documents intent. We do not tell anyone it is doing the job that server-rendered HTML is actually doing.

If you are prioritising a Friday afternoon between the two, do the HTML.

Does llms.txt help with SEO or AI search rankings?

No measurable evidence that it does either. Google has stated directly it doesn't use the file for search, and no AI assistant provider has confirmed using it for anything. It has no known effect on classic search rankings or on whether an assistant cites you.

Do ChatGPT, Claude or Perplexity actually read llms.txt files?

Essentially never, based on the available data. A May 2026 Ahrefs study of 137,210 domains found 97% of published llms.txt files received zero requests in a month, and named AI retrieval bots made up roughly 1% of the traffic the remaining 3% did receive. Domains without the file saw zero speculative requests for one — crawlers aren't checking for it the way they check for robots.txt.

Should I still publish an llms.txt file?

If it takes you five minutes, there's no harm in it — it costs nothing to serve a static file, and it's a reasonable record of intent. Just don't treat it as a fix for AI visibility, and don't spend real engineering time on it ahead of the thing that's actually load-bearing: making sure the HTML your server sends, with no JavaScript required, actually contains your content for the crawlers that matter.